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Abstract:

A stirrer stand (10) for a submersible motor stirrer (12) composed of at
least one base part (14) and a receiving part (16) for the submersible
motor stirrer beyond which a guide member extends, which is used for
guiding the submersible motor during assembly, the entire stirrer stand
being produced from a single vibration-damping material.

Claims:

1. A stirrer stand for a submersible motor stirrer comprising a foot part
and a receiving part for receiving the submersible motor stirrer, which
receiving part is overtopped by a guide member serving to guide the
submersible motor stirrer during assembly, wherein the whole of the
stirrer stand, as a shaped part comprising a foot part and a receiving
part, consists of a single, vibration-damping material.

3. The stirrer stand as claimed in claim 1, wherein the contour of the
receiving part is configured such that it receives a submersible motor
stirrer and fixes it in its working position.

4. The stirrer stand as claimed in claim 1, wherein the receiving part
has walls which absorb the reaction forces of the received submersible
motor stirrer.

5. The stirrer stand as claimed in claim 3, wherein the submersible motor
stirrer, on its side lying opposite the stirring member, has plates,
which plates bear against corresponding inner faces of walls of the
receiving part.

6. The stirrer stand as claimed in claim 1, wherein said stand is of
one-piece construction.

7. The stirrer stand as claimed in claim 1, wherein said stand is of
multi-part construction.

8. The stirrer stand as claimed in claim 1, wherein said stand can be
attached to a bottom of the basin with suitable fasteners.

9. The stirrer stand as claimed in claim 7, wherein the fasteners
comprise machine screws or chemical anchors selected from the group
consisting of adhesive dowels, reaction anchors, and shear connectors.

10. The stirrer stand as claimed in claim 1, wherein said stand has a
recess in which the guide member is disposed, and the guide member is
fixed at one or more points in the stirrer stand by bushings disposed in
said recess.

11. The stirrer stand as claimed in claim 10, wherein the bushings are
comprised of a light, elastic, pressure-resistant and vibration-damping
material.

12. The stirrer stand as claimed in claim 11, wherein the bushings are
comprised of a synthetic resin material.

13. The stirrer stand as claimed in claim 1, wherein the guide member
extends to the bottom of the basin and is fixed there.

14. The stirrer stand as claimed in claim 1, wherein the guide member is
held by a positioning mechanism disposed on the rim of the basin.

15. The stirrer stand as claimed in claim 1, wherein said stand has a
recess in which the guide member is disposed, and the guide member is
plugged, glued or cast in this recess with as little play as possible.

16. The stirrer stand as claimed in claim 1, wherein the guide member is
constructed as a hollow profile having an angular cross section.

17. The stirrer stand as claimed in claim 16, wherein the hollow profile
has a square cross section.

18. The stirrer stand as claimed in claim 1, wherein the guide member is
constructed of metal, extruded or molded plastic, reinforced cast mineral
composite, concrete or polymer concrete.

19. The stirrer stand as claimed in claim 18, wherein the guide member is
comprised of steel or cast iron.

20. The stirrer stand as claimed in claim 1, wherein the guide member is
constructed as a solid profile or as a hollow profile optionally filled
with another material.

Description:

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of international patent
application no. PCT/EP2009/007013, filed Sep. 30, 2009, designating the
United States of America and published in German on Apr. 8, 2010 as WO
2010/037530, the entire disclosure of which is incorporated herein by
reference. Priority is claimed based on Federal Republic of Germany
patent application no. DE 10 2008 050 136.0, filed Oct. 4, 2008, which
likewise is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to a stirrer stand for a submersible
motor stirrer.

[0003] Submersible motor stirrers are stirrers which are used together
with the drive under water. They are usually employed in water treatment
plants, in wastewater purification and wastewater treatment for different
process-engineering stirring functions within various fields of use. The
stirrer stand serves to position the stirrer in such a way in a
liquid-filled basin, a corresponding plant or the like that a defined
distance is maintained between the bottom of the basin and the tip of the
stirring member, on the one hand, and the tip of the stirring member and
the liquid level, on the other hand, which distance assures the best
possible working of the stirrer.

[0004] The function of the stirrer is basically to provide good flow
guidance in the respective basin or the plant in order to achieve the
respective process-engineering function, for example good intermixing of
several phases. The stirrer stand must absorb all forces and moments
which, on the one hand, arise from the work of the stirrer itself and, on
the other hand, stem from the liquid in motion in the basin or in the
flow channel and from the further phases, such as gases and liquids,
which may be contained therein. The absorbed forces and moments must be
relayed to the subsurface, for example the bottom of the basin, or
diverted into this.

[0005] Within the scope of the invention, the term stirrer stand is used.
In the same way, the stirrer stand which is present here can also be
used, however, as a stand for a turbine. While the stirrer has the
function of generating flows, of distributing temperature and gas
content, as well as microbes and further additives, e.g. for wastewater
purification, and is thus used for water treatment or for other
process-engineering processes, the function of a turbine is to absorb
energy from a flowing stream in which it is immersed and to generate
electric current.

[0006] Stirrer stands for submersible motor stirrers or turbines are
already known in different embodiments.

[0007] For instance, stirrer stands constructed of steel and consisting of
welded-together profiles are known. These steel constructions are usually
connected to the guide member, configured as a guide tube, for the
submersible motor stirrer. This enables the submersible motor stirrer,
during assembly, to be transferred via the guide member into its assembly
position and to be held there by the guide member, the absorbed forces
being transferred via the guide member to the whole of the steel
construction.

[0008] DE 39 00 630 discloses a submersible motor stirrer in which the
guide tube is fixedly connected only to the bottom of the basin and in
which two supports are provided for absorbing the reaction forces of the
stirrer comprising a motor and a propeller, which supports are fastened,
on the one hand, beneath the stirrer to the guide tube and, on the other
hand, to the bottom of the basin.

[0009] In the various basins in which the submersible motor stirrers are
disposed, irregular flows occur, so that the stirring member of the
submersible motor stirrer is impinged upon or subjected to irregular
flows. In addition, the turbulence generated by the flow around the base
frame is problematic. The irregular oncoming flows lead to vibrations
within the base frame, so that both the submersible motor stirrer and the
base frame are subjected to above-average load.

[0010] In order to produce a mounting for a submersible motor stirrer
which is as low in vibrations as possible, EP 980,704 proposes to produce
the guide member, which protrudes vertically beyond the stirrer stand and
which is there configured as a guide tube, from a first material, for
example steel, and to produce the stirrer stand itself from a second
material, for example concrete, which has different vibration
characteristics than the first material. In the installed position, the
submersible motor stirrer is still connected to the guide member
consisting of the first material. While the stirrer stand made of
concrete is now itself almost perfectly rigid, the more elastic guide
member, which, even in the installed position of the submersible motor
stirrer, is connected thereto, simultaneously absorbs a part of the
generated forces and moments.

[0011] The previously known stirrer stands have various drawbacks,
however. For instance, stirrer stands which are made entirely of
high-quality steel, are very costly and, because of the lack of internal
damping, are also very prone to vibration. The use of several materials,
which is known from EP 980,704, additionally calls for assembly and
jointing processes. The transmission of torques and forces to the guide
tube, which transmission is provided according to this solution, requires
the guide tube to have a solid design. This, in turn, leads to vibrations
in the event of fluctuating loads.

SUMMARY OF THE INVENTION

[0012] The object of the present invention is to provide a stable stirrer
stand for submersible motor stirrers which allows a mounting of the
submersible motor stirrer which is as low in vibrations as possible.

[0013] This and other objects of the invention are achieved by providing a
stirrer stand as described and claimed hereinafter.

[0014] Based on this solution, which provides a stirrer stand for
submersible motor stirrers which at least comprises a foot part and a
receiving part for the submersible motor stirrer, which receiving part,
in turn, is overtopped by a guide member which serves to guide the
submersible motor stirrer during assembly, with the entirely of the
stirrer stand being made of a single, vibration-damping material. Within
the meaning of the present invention, a vibration-damping material is a
material with a low modules of elasticity. According to the present
invention, the stirrer stand absorbs all the loads of the operating
stirrer, or of the turbine which is correspondingly accommodated as an
alternative to a stirrer. Unlike the known prior art, the guide member is
not a constituent part of the stirrer stand itself and, in the working
position of the stirrer, absorbs neither forces nor moments of the
stirrer. It serves exclusively for the positioning of the stirrer or
turbine on the stand during assembly operation, i.e. prior to use in the
respective basin. Preferred embodiments of the invention are also
described hereinafter.

[0015] Accordingly, the stirrer stand can advantageously be comprised of
concrete, cast mineral composite, cast iron or composite materials with a
low modulus of elasticity.

[0016] The contour of the receiving part is configured such that it can
receive the stirrer or a turbine and can fix it in its working position.
For this purpose, walls are advantageously provided, which walls absorb
the reaction forces of the received submersible motor stirrer or those of
the turbine. Advantageously, the submersible motor stirrer, on its side
lying opposite the stirring member, can have plates, which plates bear
against corresponding inner faces of the walls of the receiving part.
These plates can preferably be elastic and can thus serve for the
vibration damping.

[0017] Advantageously, the stirrer stand is of one-piece construction.
However, it can also in principle be multi-part, in which case the
possibility is afforded of composing it of a foot part and a receiving
part, with an optimal intermediate part arranged therebetween. For
optimal transmission of the forces and moments to the bottom of the
basin, the stirrer stand is attached to the bottom of the basin in an
advantageous manner by suitable fasteners. These fasteners can comprise,
for example, chemical anchorages, such as adhesive dowels, reaction
anchors and/or shear connectors. On the other hand, machine screws can
however be provided, even in the use of steel containers. In the case of
plastic containers, metallic bushings, for example, can be used, so that,
here too, attachments by means of machine screws is possible. All other
available and known connecting anchors can also be used, however.

[0018] The stirrer stand advantageously has a recess in which the guide
member is disposed, with the guide member being fixed at one or more
points in the stirrer stand by bushings disposed in the recess. These
bushings advantageously are comprised of a light, elastic,
pressure-resistant and vibration-damping material, preferably an
appropriate plastic.

[0019] The guide member can reach to the bottom of the basin and can be
fixed there in order to absorb the forces which arise during assembly of
the submersible motor stirrer. A thicker dimensioning of the guide member
in the region of the suspension mounting is not necessary however, since,
during operation of the submersible motor stirrer, or of the turbine used
in place thereof, the forces must be absorbed exclusively by the stirrer
stand and not by the guide member.

[0020] The guide member can also be held by a positioning mechanism
disposed on the rim of the basin. The guide member can be disposed in a
recess of the stirrer stand, in which case it is plugged, glued or cast
in the recess with as little play as possible.

[0021] Advantageously, the guide member is constructed as a hollow profile
of angular, preferably square cross section. In principle, however, any
other cross-sectional design is possible here. For instance, rectangular,
triangular, pentagonal, hexagonal or even octagonal hollow profiles, or,
indeed, polygonal profiles in general, having any number of corners, as
well as round tubes--with or without--guide ribs, can be used. In
principle, however, two or more tubes can also, be used, which tubes can
be mutually connected, though care must naturally be taken to ensure that
these are a defined distance apart and are parallel. As guide members,
double-T beams or U-profiles are also possible, however.

[0022] All hollow profiles can be lined with one or more materials in
order to improve rigidity and damping.

[0023] The guide member may be comprised of a metallic material, such as
steel, cast iron, or extruded or molded plastics. Respectively reinforced
cast mineral composite, concrete or polymer concrete can also be used, in
which case the guide member, if a hollow profile, can be selectively
lined with another material. Within the scope of the invention, guide
member can also, however, be constructed as a solid profile.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The invention will be described in further detail hereinafter with
reference to illustrative preferred embodiments shown in the accompanying
drawing figures, in which:

[0025] FIG. 1 is a schematic representation of a stirrer stand with a
fitted motor stirrer;

[0026] FIG. 2 is a perspective detail view of the apparatus according to
FIG. 1;

[0027] FIG. 3 is a perspective view of the stirrer stand in an oblique
view from above;

[0028] FIG. 4 is a perspective view of the stirrer stand of FIG. 3 in an
oblique view from below;

[0029] FIG. 5 is a longitudinal sectional view through a stirrer stand
according to FIGS. 3 and 4;

[0030] FIG. 6 is a perspective view of a submersible motor stirrer with an
attached stirring member, and

[0031] FIG. 7 is a different perspective view of the submersible motor
stirrer according to FIG. 6.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0032] FIG. 1 shows a stirrer stand 10, which in this embodiment is
produced as a one-piece concrete shaped part and comprises a foot part 14
and a receiving part 16. As is made clear in FIG. 1, the contour of the
receiving part 16 is configured such that it can receive a submersible
motor stirrer 12, as represented here, or else, alternatively thereto, a
turbine, and fixes it in its working position. The submersible motor
stirrer 12 has a stirring member 20, here configured as a twin-bladed
propeller. The stirrer stand 10 is overtopped by a guide member 18, which
is only partially shown in FIG. 1. This guide member 18, which is here
configured as a steel tube having a square cross section, serves merely
for the guidance of the submersible motor stirrer 12 during vertical
movements. To this end, the submersible motor stirrer 12 has on the side
facing away from the stirring member 20 a sliding carriage or mounting,
consisting, as far as possible, of plastic sheets, in order here to allow
guidance along the guide member 18. The submersible motor stirrer can
hence be lowered or lifted out over a longer distance from the rim of the
basin to the receiving part of the stirrer stand. Following assembly of
the submersible motor stirrer in the receiving part 16, the guide member
18 no longer fulfils any further mounting or guidance functions of the
submersible motor stirrer.

[0033] That assembly state of the submersible motor stirrer 12 in the
receiving part 16 which is depicted in FIG. 2 is served, first of all, by
corresponding walls 22 configured in the receiving part 16 of the stirrer
stand 10. Bearing directly against these walls is that respective end of
the submersible motor stirrer which lies opposite the stirring member 20,
the submersible motor stirrer supporting corresponding plates 24 (cf.
also FIGS. 6 and 7), which bear squarely against the inner faces of the
walls 22. The rear plates 24 (visible in FIG. 7) thus transmit the axial
thrust and/or the reaction forces of the submersible motor stirrer to the
vertical inner face of the walls 22 and from there into the stirrer stand
10. The lateral plates 24 absorb the reaction torque force of the
submersible motor stirrer and transmit it to the corresponding faces of
the walls 22 of the receiving part 16. The front part of the submersible
motor stirrer 12 rests via a flange-like ring 30 against a corresponding
annular recess 32 of the receiving part.

[0034] In the operating state, the stirrer stand 10 with the installed
submersible motor stirrer 12 is arranged fully submerged in a basin (not
shown here).

[0035] The attachment to the bottom of the basin, which will probably
generally be a concrete floor, is usually realized with chemical anchors
(not shown in detail here). Usual examples include adhesive dowels,
reaction anchors or shear connectors. Insofar as the stirrer stand is
disposed in a steel container, machine screws can here be provided as
anchors. In the illustration according to FIG. 4, six through holes 34
are provided for this purpose. Insofar as the basin comprises a plastic
container, metallic bushings can also be used here, so that machine
screws, which can be placed through the through holes 34 in the stirrer
stand 10, can also be used here as anchors.

[0036] For an optimal full-faced support of the stirrer stand 10, a
compensating mass, in the form of a bottom casting or cartridge, can be
used on an uneven floor, consisting, for example, of concrete. These
measures are already known from the prior art and are therefore not shown
diagrammatically in greater detail here.

[0037] Alternatively, the stirrer stand 10 could also be positioned in a
depression in the bottom of the basin and cast or glued in place there,
as is realized, for example, in the field of assembly of lighting masts
or overhead line masts for railways.

[0038] From the representation according to FIG. 5, it can be seen that a
recess 28 is provided in the stirrer stand 10 through which the guide
member 18 is placed. This is advantageously fixed in the region of the
bottom of the basin. The guide member can be held in the recess 28 by the
two plastics bushings 26 which are comprised of a slightly elastic,
pressure-resistant and vibration-damping plastic. In a manner which is
not represented here, the top side of the guide member 20 projects beyond
the liquid level and is either free-standing or its upper region may be
fastened by a mounting to the rim of the basin, a bridge or a transverse
beam.

[0039] In the embodiment which is shown here, the guide member 18 can have
comparatively small dimensions, since, during operation of the
submersible motor stirrer 12, it does not have to absorb any forces and
moments therefrom. Instead it has a pure guidance function for
positioning of the submersible motor stirrer 12 on the stirrer stand 10.
The guidance member is acted upon only by forces resulting from the
oncoming flow, i.e. the flow forces of the liquid contained in the basin,
as well as the mechanical influences generated in connection with the
ventilation of the basin content.

[0040] The foregoing description and examples have been set forth merely
to illustrate the invention and are not intended to be limiting. Since
modifications of the described embodiments incorporating the spirit and
substance of the invention may occur to persons skilled in the art, the
invention should be construed broadly to include all variations within
the scope of the appended claims and equivalents thereof.